Information recording device and information reproducing device

ABSTRACT

The information reproduction device for reproducing contents information based on license information added to the contents information and required for reproducing the contents information, includes a determining section for determining whether encrypted contents information is the officially copied contents information or privately copied contents information based on the contents of the license information, and a reproduction section configured to reproduce the contents information determined as the privately copied contents information by the determining section under more severe restriction than the officially copied contents information. Thus, the contents copied by the proper route (officially copied contents) can be distributed in a more advantageous form than the contents copied without proper authorization.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 11-058890, filed Mar. 5, 1999,the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to devices for recording and reproducingthe contents, including images, voice data and the like.

The digital contents reproduction devices including a CD player arepopularly accepted because of clear tone quality and less degradation oftone quality caused by long-term use. However, it has become possible tocopy digital contents free of degradation by faithfully duplicating itbit by bit, and in actuality such devices have already beencommercialized. The presence of such copying device is a great advantageto the contents user, but for the contents provider, it is not desirablebecause such device exerts tremendous influence on the sales ofcontents.

Consequently, the contents provider copes with new digital devices (andmedia) when they are commercialized by not providing them with thecontents. However, this condition causes big interference topopularization of new electronic devices, and prevents not only almostall people from enjoying the convenience but also contents providersfrom enjoying business chances.

On the other hand, the privately copied contents for the user to enjoythe contents personally is the right authorized by the Copyright Law,and in actuality, for many electronic devices, the privately copiedcontents has been admitted with some restriction to the duplicationsystem (restriction to the analog recording, etc.). However, whendigital recording becomes the mainstream in years to come, it becomesdifficult to determine the privately copied contents from officiallycopied contents, and at the same time, it becomes difficult to determinewhether the copy is the privately copied contents or the authorizedcopied contents.

By the way, in this invention, the privately copied contents means thecopy for local use and carried out by the person who has no dealershipof the relevant source (digital contents), while the officially copiedcontents means the copy for global use and carried out by the person whohas the dealership to the relevant source. That is, the officiallycopied contents are only able to be acquired by the means equivalent tothe conventional contents sales, which include the sales from anelectronic shopping mall on the Internet.

BRIEF SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide aninformation reproduction device, an information recording device, andinformation selling device, and an information purchasing device, and anautomatic information vending machine, which can increase demands forofficially copied contents on the official market and build up theinformation distribution mechanism suited for interest of the contentsprovider, contents user, and electronic device manufacturer by changingover the reproduction system of the relevant contents by determiningwhether the contents are the officially copied contents or privatelycopied contents, and permitting more advantageous utilization form forthe officially copied contents than for the privately copied contents.

According to the present invention, in order to solve theabove-mentioned problems, by controlling the use of contents by licenseinformation corresponding to the contents and at the same time, pastinga digital signature to the license information corresponding to theencrypted contents, which is the officially copied contents, with asecret key of an public key cryptosystem which the contents sellingserver only knows, the officially copied contents and privately copiedcontents are determined by the presence of the digital signature, andthe reproduction system of the contents are varied based on the judgmentresults.

The information reproduction device according to the present inventionreproduces the contents information based on the license informationrequired for reproducing the contents information added to the contentsinformation and comprises a determining section configured to determinewhether the encrypted contents information is officially copied contentsinformation or privately copied contents information and a reproductionsection for reproducing the contents information determined as theprivately copied contents information with restrictions much severerthan for the officially copied contents information.

It may be determined whether the contents are the officially copiedcontents information or privately copied contents information based onthe verification information for verifying the officially copiedcontents contained in the license information.

The utilization condition of the contents information contained in thelicense information is more restricted for the privately copied contentsinformation than for the officially copied contents information.

The license information added to the contents information may beencrypted or decrypted by the key information prepared based on theinformation dependent on the identifier of the recording medium in whichthe contents information is recorded.

The judging section may determine whether the contents information isthe original contents pursuant to the contents of the licenseinformation, and if it is determined to be the original contentsinformation, the second reproduction section for reproducing thecontents information without restriction may be further included.

According to the information reproduction device of the presentinvention, a structural difference is provided in the reproductionsystem of privately copied contents as well as officially copiedcontents and original contents, and expansion of the personal use isprevented with privately copied contents admitted, thereby protectingthe copyright and contents providers. In addition, if the contents areunjustly transferred to a separate recording medium, that is, copied,since the license information is dependent on the recording medium, thelicense information is unable to be decrypted from the illegal copyingmedium, and as a result, the contents are unable to be decrypted.Therefore, whether it is privately copied contents or officially copiedcontents, the license information must be remade for the copy, andbecause it is the just recording device that can do it (for example,that knows the function “f”), restriction to number of copies isaccurately carried out, and unjust use of the contents are able to beprevented.

A first information recording device according to the present inventionis an information recording device for recording the contentsinformation (may be encrypted and may not be encrypted) and the licenseinformation (may include a decrypting key for the encrypted contentsinformation) required for reproducing the contents information and addedto the contents information, the information recording device comprisinga determining section for determining the type of input contentsinformation, a generating section for generating the license informationbased on the type determined by the determining section, the informationdependent on the identifier of the recording medium, and a recordingsection for recording the contents information to the recording mediumtogether with the license information generated by the creation section.The license generating section may generate the license informationbased on the utilization condition of contents information in additionto the type determined by the determining section and the informationdependent on the identifier of recording medium.

The contents information to be input may be restricted to analogsignals.

According to the first information recording device according to thepresent invention, discriminating the type of contents and providing theenvironment in which duplication is allowed only by the severerestrictions than the source contents differentiate the privately copiedcontents from the officially copied contents put on the official marketand relatively increase the value of the officially copied contents,thereby contributing to the expansion of market of officially copiedcontents. In addition, when the contents are unjustly transferred toanother media, that is, copied, since the license information isdependent on the media, for example, the license information is unableto be decrypted, and the license information must be re-generated forcopying whether it is privately copied contents or officially copiedcontents, and this is only achieved by a proper recording device (forexample, that knows the function “f”), and the number of copy times isable to be definitely restricted, and therefore, the unjust use is ableto be prevented. Furthermore, restricting the recorded source contentsto analog contents only can cause quality degradation of the contentsevery time duplication is made when the digital contents are recorded,and this could serve as the deterrent of duplication and at the sametime relatively increase the value of officially copied contents, andthereby the sale market of the officially copied contents are able to besecured more definitely.

A second information recording device according to the present inventionis an information recording device for recording contents informationand license information added to the contents information and requiredfor reproducing the contents information in a recording medium,comprising a generating section for generating the license informationincluding verifying information for verifying that the licenseinformation is the officially copied contents based on the informationdependent on the identifier of the recording medium and the utilizationcondition of the contents information, and a recording section forrecording the contents information as well as the license informationgenerated by the generating section to the recording medium.

The second information recording device is able to be used for thecontents selling device and contents purchasing device for selling andpurchasing the officially copied contents. For the license information,since the license information dependent on the recording medium isgenerated, whether it is the privately copied contents or officiallycopied contents, the license information must be re-generated for thecopy, and the device allowed to do this is only the proper recordingdevice (for example, that can know the function “f”), and the number ofcopies is able to be definitely restricted, and thereby unjust use isable to be prevented.

Additional objects and advantages of the present invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the present invention.

The objects and advantages of the present invention may be realized andobtained by means of the instrumentalities and combinations particularlypointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe present invention and, together with the general description givenabove and the detailed description of the preferred embodiments givenbelow, serve to explain the principles of the present invention inwhich:

FIG. 1 is a diagram showing one example of data configuration of digitallicense information;

FIG. 2 is a diagram showing one example of data configuration ofencrypted digital license;

FIG. 3 is a diagram showing one example of data configuration of licenseheader contained in the digital license information;

FIG. 4 is a diagram showing one example of data configuration ofcontents utilization condition contained in the digital licenseinformation;

FIG. 5 is a diagram showing one example of data configuration of theanalog license information;

FIG. 6 is a diagram showing one example of data configuration of digitalsignature;

FIG. 7 is a diagram showing one example of data configuration of thedigital signature header contained in the digital signature;

FIG. 8 is a diagram showing a configuration example of contentsreproduction device of the first embodiment according to the presentinvention;

FIG. 9 is a diagram showing a configuration example of the originalcontents reproduction section of FIG. 8;

FIG. 10 is a diagram showing a configuration example of privately copiedcontents reproduction section of FIG. 8;

FIG. 11 is a diagram showing a configuration example of officiallycopied contents reproduction section;

FIG. 12 is a flowchart for explaining the processing operation of thecontents reproduction device of FIG. 8;

FIG. 13 is a flowchart for explaining the reproduction processingoperation of the original contents;

FIG. 14 is a flowchart for explaining the privately copied contentsreproduction processing operation;

FIG. 15 is a flowchart for explaining the officially copied contentsreproduction processing operations;

FIG. 16 is a diagram showing a configuration example of encryptedcontents decrypting section included in the officially copied contentsreproduction section of FIG. 11;

FIG. 17 is a diagram showing a configuration example of encryptedlicense decrypting section included in the encrypted contents decryptingsection of FIG. 16;

FIG. 18 is a flowchart for explaining the encrypted contents decryptingprocessing operation;

FIG. 19 is a flowchart for explaining the encrypted license decryptingprocessing operation;

FIG. 20 is a diagram showing other example of encrypted digital licenseinformation, where the digital signature is not externally added;

FIG. 21 is a diagram showing a configuration example of the contentsrecording device of the second embodiment according to the presentinvention;

FIG. 22 is a diagram showing the configuration example of privatelycopied contents generating section of FIG. 21;

FIG. 23 is a diagram showing a configuration example of the originalcontents generating section of FIG. 21;

FIG. 24 is a flowchart for explaining the processing operation of thecontents recording device of FIG. 21;

FIG. 25 is a flowchart for explaining the privately copied contentsgenerating processing operation;

FIG. 26 is a flowchart for explaining the privately copied contentsgenerating processing operation;

FIG. 27 is a flowchart for explaining the original contents generatingprocessing operation;

FIG. 28 is a flowchart for explaining the original contents generatingprocessing operation;

FIG. 29 is a flowchart for explaining the original contents generatingprocessing operation;

FIG. 30 is a diagram showing one example of data configuration of copiedform information;

FIG. 31 is a diagram showing one example of data configuration ofutilization condition information in the copied form information of FIG.30;

FIG. 32 shows a configuration example of the contents recording deviceof the sixth embodiment according to the present invention, where thesource contents are restricted to analog contends only;

FIG. 33 is a flowchart for explaining the processing operation of thecontents recording device of FIG. 32;

FIG. 34 is a flowchart for explaining the processing operation of thecontents recording device of FIG. 32;

FIG. 35 is a diagram showing a configuration example of the contentsselling device of the seventh embodiment according to the presentinvention;

FIG. 36 is a diagram showing a configuration example of the licensegenerating section of the contents selling device of FIG. 35;

FIG. 37 is a flowchart for explaining the processing operation of thecontents selling device of FIG. 35;

FIG. 38 is a flowchart for explaining the license generating processingoperation;

FIG. 39 is a diagram showing one example of data configuration ofpurchase requesting information;

FIG. 40 is a diagram showing a configuration example of the contentspurchasing device;

FIG. 41 is a flowchart for explaining the processing operation of thecontents purchasing device; and

FIG. 42 is a flowchart for explaining the processing operation of thecontents purchasing device of FIG. 40.

DETAILED DESCRIPTION OF THE INVENTION

A preferred embodiment of an information recording/reproduction deviceaccording to the present invention will now be described with referenceto the accompanying drawings.

First Embodiment

First, the terms used in the following description will be defined.

License information falls into two broad general categories: one to beembedded in the contents information itself and the external informationrelated to the contents information as additional information. Theformer is achieved in the analog layer by an electronic water-marktechnique, and is called the analog license information in this case.The latter is achieved in a digital layer and therefore called thedigital license information. Furthermore, the two are jointly called thelicense information.

Contents can be classified into four kinds as shown in the table below:legacy contents, plain contents, or analog contents (hereinafter calledthe analog contents), original contents, officially copied contents forglobal use, and privately copied contents for local use.

TABLE 1 Medium- Kind Signature Compression Encryption dependencyOfficially Yes Yes Yes Yes Copied Contents Privately No Yes No YesCopied Contents Original No Yes No No Contents Analog No No No NoContents

The original contents information is either the contents information ofone's own work or the copy-free contents information with no specificrestriction to use. Consequently, the original contents information iscompressed but not encrypted, not medium-dependent (prevents free copyto other medium), free of digital signature, and with the addition ofthe digital license information with the license header only laterdiscussed.

The officially copied contents information means the contentsinformation encrypted by the person who possesses the selling right ofthe contents information. The officially copied contents information hasnot only the contents information compressed and encrypted but also hasthe addition of the digital license information with the digitalsignature that certifies the sales right. It is medium-dependent and isunable to be freely copied to other medium.

The privately copied contents information means the contents informationcopied by the person who has no selling right of the contentsinformation. The privately copied contents information has the contentsinformation compressed and encrypted as well as has the addition ofdigital license information only with the license header free of digitalsignature.

Next discussion will be made on the specific construction of the digitallicense information. The digital license information Lo comprises thelicense header (LH), contents key (Kc), contents utilization condition(U), certificator MAC, and digital signature.

The license header is data of fixed length comprising the length oflicense information shown in FIG. 3, contents identifier (ID), copyinformation, and contents key length. The length of license informationshows the total length of the license information and is utilized whenlicense is extracted. The copy information is the information fordetermining whether the contents information is original contentsinformation, officially copied contents information, or privately copiedcontents information. The length of the contents key shows the length ofcontents key contained in the license information.

The contents utilization condition U in the digital license informationshows the utilization condition of the contents informationcorresponding to the digital license information, and has theconfiguration shown in FIG. 4. In FIG. 4, the digital output flag Fe,when “1,” permits the digital output of the contents information anddoes not permit when “0.” The effective date information shows theeffective date of the contents information. Similarly, the effectivenumber of times shows the number of times in which the contentsinformation is utilized. These are all data of fixed length specified bythe system.

By the way, the digital license information shown in this specificationis only an example, and are varied in various ways in accordance withapplication forms.

The certificator is the data for determining whether or not the contentskey and contents utilization condition contained in the digital licenseinformation is correct, and has effects of error detection andtamper-proof.

The digital signature comprises a digital signature header and digitalsignature as shown in FIG. 6. The digital signature header comprises thetotal length (bit length) of the digital signature and the kind of thedigital signature and the signature verification key No. as shown inFIG. 7.

Because the digital license information Lo contains the contents key Kc,it must be encrypted. However, on the other hand, encrypting all thedigital license information gives rise to the need of decrypting onlyfor acquiring the copy information or the need of encrypting those whichoriginally do not need encryption such as the original contentsinformation. To avoid this, in the present embodiment, a configurationthat limits the scope of encryption only to the contents key, contentsutilization condition, and certificator as shown in FIG. 2.

Hereinafter, the data in which the information I is encrypted by key Kis expressed with I[K] or [K]I. For encrypting the digital licenseinformation and the contents information, the use of common keyencryption is premised. The common key encryption is an encryptiontechnology in which the encryption key and decryption key coincide. Inthe following embodiment, there are descriptions to encrypt with adecryption key or to decrypt with an encryption key depending on thecontext, but this does not contradict because of the foregoing reasons.

The encrypted digital license information has the structure as shown inFIG. 2 and the part excluding the license header and the digitalsignature is encrypted by the license key later described in detail.

Next description will be made on the analog license information. Theanalog license information is embedded in the contents informationitself as the electronic water-mark, and since it is embedded in thereproduced plain contents information, it is still effective even if thecopyright protection of the contents by encryption is broken. However,on the other hand, since the information is embedded in the contentsinformation itself, it has a defect to take time for embedding.

Therefore, in the present embodiment, for the analog licenseinformation, the structure as shown in FIG. 5 is considered. That is,the analog license information La comprises the copy time restrictioninformation and copy information, and the copy time restrictioninformation indicates the upper limit value of the number of copies (norestriction included) of the contents information, and the copyinformation is the information same as the copy information contained inthe license header LH of FIG. 3.

Hereinafter, as the first embodiment of the present invention, acontents reproduction device that determines whether the input digitalcontents information is at least officially copied contents informationor privately copied contents information, and even original contentsinformation according to circumstances based on the encrypted digitallicense information and varies the reproduction system of the contentsbased on the determination results.

The overall configuration diagram of the contents reproduction device ofthe first embodiment according to the present invention is shown in FIG.8 and the flow of processing is shown in the flowchart of FIG. 12.Referring now to the flowchart of FIG. 12, the contents reproductiondevice of FIG. 8 is described. For the contents information, the digitalcontents information (encrypted contents information (Kc[C]) or notencrypted contents information C) is input together with the encrypteddigital license information L.

First of all, by the reproduction instruction from the reproductioninterface (IF) section 3, contents information Kc[C] and encrypteddigital license information L are input in the contents input section 2(step S1). These pieces of information is sent to the whole controlsection 1, and referring here to the license header of the encrypteddigital license information, whether the contents information is theoriginal contents information or privately copied contents information,or officially copied contents information is determined (steps S2 tostep S4). Based on the determination results, reproduction processing ofthe original contents information, reproduction processing of theprivately copied contents information, and reproduction processing ofthe officially copied contents information is carried out (steps S6 tosteps S8).

Because those which do not correspond to these three kinds of contentsare contents which are unable to be interpreted in the contentsreproduction device according to the present invention, an error outputis generated, and processing is ended (step S5).

The reproduction processing for each contents information based on thethree kinds is carried out in relevant reproduction sections 4, 5, and 6of FIG. 8. These specific configuration and the flow of processing willbe later described, but it is important to achieve a configuration inwhich the contents information is allowed to flow from the officiallycopied contents reproduction section 5 to both analog output section 8and digital output section 7, but not allowed to flow from the privatelycopied contents reproduction section 4 to the analog output section 8only. The analog output section 8 is defined to be of relatively lowquality and to output under the non-compressed state, and to include notonly analog signal outputs but also low-bit-rate digital signal output.The digital output section 7 is defined to be of relatively high qualityand to output under the compressed state, and not to include analogsignal output. That is, the privately copied contents information isallowed to be reproduced only for the purpose of local use, and withrespect to the secondary utilization such as cutting and pasting part ofthe contents information, there is a high possibility for the user todeviate from the scope of the personal use and the contents provider isunable to permit. In the present invention, in view of this point,structural differences are provided for the method of reproducing theprivately copied contents information and officially copied contentsinformation, or original contents information, and by preventingexpansion of the use of privately copied contents information whileadmitting the recording of the privately copied contents information,the copyright and the contents provider are protected.

The configuration diagram of the original contents reproduction section6 of FIG. 8 is shown in FIG. 9, and the flow of the processing in FIG.13. The original contents information is the non-encrypted contentsinformation as described above, and is also referred to as the plaincontents information. With respect to the license information, in thepresent embodiment, the digital license information comprises a licenseheader only, and with respect to the analog license information, anunrestricted number of copies is set.

Referring now to the flowchart of FIG. 13, the reproduction section 6 ofthe original contents information of FIG. 9 is described.

The original contents information C is input in the contents inputsection 6 c (step S21), the compression system such as MPEG, etc. isdepressed or decompressed at the data decompressing section 6 f (stepS22), and the digital contents information C outputted as a result isconverted from the digital signal to the analog signal (D/A conversion)at the D/A converting section 6 g (step S23). And if the analog licenseinformation La embedded in the contents information is detected at theanalog license information detecting section 6 d (step S24), the controlsection 6 a determines whether the contents information is the originalcontents information or not by referring to the copy information therein(step S25). If it is not the original contents information, the error isoutputted and processing is ended at the moment (step S29). If it is theoriginal contents information, the control section 6 a determineswhether the digital output instruction is provided or not. If thedigital output instruction is provided (step S26), the digital signal Cdis outputted via the digital output section 6 e (step S30), andotherwise, the digital contents information C is converted from thedigital signal to the analog signal Ca at the D/A converting section 6 gand outputted via the analog output section 6 h (steps S27-S28).

FIG. 10 shows the configuration diagram of the privately copied contentsreproduction section 4 of FIG. 8 and FIG. 14 shows the flow of theprocessing. As described above, the privately copied contentsinformation is the contents information which is encrypted and whichdoes not contain the digital signature for certifying that it is theofficially copied contents information in the digital licenseinformation.

Referring now to the flowchart of FIG. 14, the privately copied contentsreproduction section 4 of FIG. 10 will be described in detail.

The privately copied contents information Kc[C] is input in theencrypted contents inputting section 4 b together with the encrypteddigital license information L (step S31). These pieces of information issent to the encrypted contents decrypting section 4 c, where theencrypted digital license information L is decrypted by the processinglater described in detail (step S32), and the encrypted contentsinformation Kc[C] is decrypted using the contents key Kc contained inthe digital license information. In addition, from the digital licenseinformation, the utilization condition U is extracted (steps S33-S35).

The control section 4 a checks the utilization condition U (step S36),and if it is determined inapplicable, it outputs the error and ends theprocessing (step S42). If it is determined applicable, the controlsection 4 a determines whether the conditions stated in the utilizationcondition U deviate from the range (upper limit) permitted to theprivately copied contents information or not. This is to cope withtampering etc. of the application conditions, and if it deviates, thecontrol section 4 a sets the condition to the upper limit value andadvances to step S37, or outputs the error to end the processing (stepS42). By doing this, it is able to cope with forgery of licenseinformation as a system.

The control section 4 a feeds the decrypted contents information C tothe data decompressing section 4 d, decompresses the compression datasuch as MPEG data, etc., and outputs the digital contents information Cd(step S37). After the digital contents information Cd is converted fromthe digital signal to the analog signal by the D/A converting section 4e (step S38), the analog license information detecting section 4 fdetects the analog license information embedded in the contentsinformation (step S39). The control section 4 a determines whether thecontents information is privately copied contents information or not byreferring to the copy information in the analog license information(step S40). If it is not the privately copied contents information, thecontrol section outputs the error and ends at the moment (step S43). Ifit is the privately copied contents information, it is D/A converted bythe D/A converting section 4 e and the analog contents information Ca isoutputted via the analog output section 4 g (step S41). By the way, evenif the digital output instruction is provided, the digital output is notcarried out.

FIG. 11 shows the configuration diagram of the officially copiedcontents reproduction section 5 of FIG. 8 and FIG. 15 shows the flow ofthe processing. As described above, the officially copied contentsinformation is the contents information which is encrypted and whichcontain the digital signature for certifying that it is the officiallycopied contents information in the digital license information.

Referring now to the flowchart of FIG. 15, the officially copiedcontents reproduction section 5 of FIG. 11 will be described in detail.

The officially copied contents information Kc[C] is input in theencrypted contents inputting section 5 b together with the encrypteddigital license information L (step S51). These pieces of information issent to the encrypted contents decrypting section 5 c, where theencrypted digital license information L is verified whether the digitalsignature is added to the encrypted digital license information by theprocessing later described in detail, and if it is added, theinformation is verified for the officially copied contents informationby verifying the digital signature using the digital signatureverification key (steps S52-S53). If the digital signature is not addedin step S52, or if the digital signature is not verified in step S53,the error is outputted and processing is ended (steps S64-S65).

If the digital signature is able to be verified at step S53, theencrypted digital license information is decrypted by the processinglater described in detail (step S54) and the encrypted contentsinformation is decrypted using the contents key Kc included in thedigital license information. In addition, the utilization condition U isextracted from the digital license information (steps S55-S57).

The control section 5 a checks the utilization condition U (step S58),and if it is determined inapplicable, it outputs the error and ends theprocessing (step S66). If it is determined applicable, the controlsection 5 a determines whether the conditions stated in the utilizationcondition deviate from the range (upper limit) permitted to theprivately copied contents information or not. If it deviates, thecontrol section sets the condition to the upper limit value and advancesto step S59, or outputs the error to end the processing. By doing this,it is able to cope with forgery of license information as a system.

The control section 5 a feeds the decrypted contents information C tothe data decompressing section 5 d, decompresses the compression datasuch as MPEG data, etc., and outputs the digital contents information Cd(step S59). After the digital contents information Cd is D/A convertedby the D/A converting section 5 e (step S60), the analog licenseinformation detecting section 5 f detects the analog license informationembedded in the contents information. The control section 5 a determineswhether the contents information is officially copied contentsinformation or not by referring to the copy information in the analoglicense information (step S61). If it is not the officially copiedcontents information, the control section outputs the error and ends atthe moment (step S67). If it is the officially copied contentsinformation, when the digital output instruction is provided (step S62),the digital contents information Cd is D/A converted via the digitaloutputting section 5 i (step S68), and if not, the digital contentsinformation Cd is D/A converted by the D/A converting section 5 e andthe analog contents information Ca is outputted via the analog outputsection 5 g (step S63).

Next description is made on the encrypted contents decrypting sections 4c, 5 c contained in the privately copied contents reproduction section 4(FIG. 10) and the officially copied contents reproduction section 5(FIG. 11). This configuration section exists in the privately copiedcontents reproduction section 4 and officially copied contentsreproduction section 5, and both have similar configurations. First,discussion will be made on the encrypted contents decrypting section 5 cof the officially copied contents reproduction section 5, and withrespect to the encrypted contents decrypting section 4 c of theprivately copied contents reproduction section 4, the difference fromthe encrypted contents decrypting section 5 c only will be discussed.

FIG. 16 shows a configuration example of the encrypted contentsdecrypting section 5 c and FIG. 18 shows the flow of the processing.Referring now to the flowchart of FIG. 18, the encrypted contentsdecrypting section 5 c is described.

When the decrypted contents information Kc[C] and decrypted digitallicense information L are inputted to the encrypted license decryptingsection 5 c (step S71), at the encrypted license decrypting section 5 c,the media ID, which is the identifier of media M in which the contentsinformation is recorded is acquired through the media ID extractingsection (in the case of the officially copied contents reproductionsection 5, through media ID extracting section 5 h and in the case ofthe privately copied contents reproduction section 4, through media IDextracting section 4 h) (step S72). Using the media ID, a licensedecrypting key w is prepared by the section later discussed in detail,and the decrypted digital license information is outputted (step S73).

Of the digital license information shown in FIG. 1, the certificator iscalculated from the contents key Kc and the contents utilizationcondition U (step S75). The certificator should be such a value that anoutput of one-directional function to which the informationconcatenating, for example, the contents key with the contentsutilization condition are inputted.

The role of the certificator in this event is to detect the error sothat the erroneous contents decryption key or utilization condition dueto the erroneous license key w is not outputted. Generation of thecertificator is achieved by the one-directional function. Theone-directional function is able to be achieved by the hash function orencryption function, and is the function which is unable to estimate theinput value from the output value.

The MAC collating section 102 collates the certificator calculated fromthe output of the encryption license decrypting section 101 with thecertificator MAC originally contained in the digital license informationof FIG. 1 also outputted from the encryption license decrypting section101 (step S76), determines that the outputted contents decryption key Kcis reliable if they coincide (step S77), and using this Kc, decrypts theencrypted contents information by the contents decrypting section 103(step S78). If the certificators do not coincide, the error is outputtedto end the processing (step S81).

When the certificators are collated and the encrypted contentsinformation is decrypted, the contents information C and the utilizationcondition U are outputted, and processing of the encrypted contentsdecrypting section is ended (step S79).

Next discussion is made in detail on the encrypted license decryptingsection 101, which is a component element of the encrypted contentsdecrypting section 5 c. The configuration is shown in FIG. 17 and theflow of the processing is shown in FIG. 19.

Referring now to the flowchart shown in FIG. 19, the encrypted licensedecrypting section 101 is described.

When the encrypted digital license information L is inputted (step S91),first, at the digital signature detecting section 101 a, detection ofthe digital signature takes place (step S92). That is, the digitalsignature is detected by the use of the data in the license header, forexample, using the following formula, the head address of the digitalsignature is calculated.

Head  address  of  the  digital  signature = head  address  of  the  encrypted  digital  license  information  + (license  header  length + contents  key  length + length  of  contents  utilization  condition  + length  of  certificator)

The digital signature verification key acquiring section 101 b acquiresthe fixed-length digital signature header from the head address of thisdigital signature (see FIGS. 6 and 7), and based on the total length ofthe digital signature stated in it, kind of signature, and number ofsignature detection key, the signature algorithm and the verificationkey are specified. When the kind of signature and the number ofsignature verification key are acquired, based on this, the digitalsignature verification key storing section 101 f is searched, and thekind of the signature, signature algorithm corresponding to the numberof the signature verification key, and the verification key are acquired(step S94).

When the digital signature (header) is unable to be detected, the erroris outputted and processing is ended (steps S93, S101).

When the digital signature is detected, then, the digital signatureverifying section 101 c verifies the detected digital signature by theuse of the signature algorithm specified by the digital signature headerand the signature verification key of the signature verification keynumber (step S95).

The digital signature here is assumed to be the signature by the publickey cryptosystem. That is, the authorized server or distributor with thesignature creation key (secret key) only is able to generate the licensefile that corresponds to the officially copied contents information.Even if any one other than those possesses a reproduction device, whatexists in the reproduction device is the signature verification key(public key) only. Because the difficulty to find the secret key fromthe public key guarantees the safety of the public key cryptosystem, theuse of the sufficiently safe public key cryptosystem can prevent thecreation of the digital signature corresponding to the third party whodoes not know the secret key. This guides to the notion in that theparty that can generate the license corresponding to the officiallycopied contents information is the authorized distributor. However, onthe other hand, the public key cryptosystem is not always safe becauseof the development of the attack method (deciphering method). In view ofthis, it is constructed to specify and change the signature algorithmand signature verification key as required in the header of the digitalsignature.

When the signature verification result is determined to be NG in thedigital signature verifying section 101 c, the error is outputted (stepsS96, S102). Otherwise, the license key generating section 101 d acquiresthe media ID (MID) of the media in which the encrypted contentsinformation is recorded (step S97), and using the function “f” secretlyheld in the reproduction device, the license key w dependent on themedia is obtained from the equation:w=f(MID)

(step S98).

This is a mechanism for preventing decryption of the encrypted digitallicense information and as a result disabling the decryption of thecontents information because only the license key w dependent on themedia is obtained when the contents information is transferred to othermedia, that is, when the contents information is copied.

In this way, whether it is the privately copied contents information orofficially copied contents information, for copying, the encrypteddigital license information must be re-generated, but since the devicethat can achieve this is a proper recording device that knows thefunction “f”, restriction to the number of copies is definitely carriedout, and the unjust use is thereby prevented. In this sense, it isdesirable that the hardware or firmware that realizes the function “f”exists in tamper-proof LSI.

The license decrypting section 101 e decrypts the encrypted digitallicense information using the license key w generated in this way (stepS99), obtains and outputs the digital license information Lo (stepS100).

This completes description of the encrypted contents decrypting section5 c of the officially copied contents decrypting section 5 and theencrypted license decrypting section 101 which is the component element.The encrypted license decrypting section 101 of the encrypted contentsdecrypting section 4 c of the privately copied contents reproductionsection 4, and the digital signature detecting section 101 c of FIG. 17,digital signature verification key acquisition section 101 b, digitalsignature verification key storing section 101 f, and digital signatureverification section 101 c are not required as configuration andprocessing of these is not required.

Next description is given on several variations of the contentsreproduction device discussed above.

First of all, in the overall configuration of FIG. 8, a case in whichthe reproduction section that is different in accordance with the typeof contents information is installed completely independently is shown,but this is not always required. Practically, reproduction processingvaries in accordance with the type of the license file, but as describedabove, there are many parts in which processing is similar.Consequently, bringing the parts which carry out the same processing toone circuit can reduce the circuit scale. Conversely, even in thecircuit which has the same functions, changing specifications for eachreproduction section can improve the safety. For example, using adifferent algorithm for each kind of contents information in the datadecompressing sections 4 d, 5 d, and 6 f, respectively, of eachreproduction section makes it difficult to falsify the kind of contentsinformation by tampering the license information.

A configuration of the reproduction device that does not have theoriginal contents reproduction section 6 is able to be considered. Insuch event, the original contents information is unable to be reproducedon the reproduction device side, and the contents information is limitedto two kinds: officially copied contents information and privatelycopied contents information. By doing this, there is a problem in thatthe self-made contents information is regarded as the privately copiedcontents information, but on the other hand, there can be avoided theproblem of recording and unconditionally reproducing non-self-madecontents information such as dubbing of contents information from radioor TV.

With respect to the digital signature, in addition to adding the licenseinformation as in the case of FIG. 1, a form to carry out doubleencryption and affix the signature may be accepted, in which encryptionis carried out by the signature creation key Ks after encryption by thelicense key w is carried out. The determination whether decryption isproperly carried out or not is definitely made by the certificator MACso that decryption is unable to be properly carried out even in theconfiguration as shown in FIG. 20, or whether the contents informationis decrypted by different signature creation key or with a correctsignature verification key. By doing this, the data size of the digitalsignature can be reduced.

According to the first embodiment, it is possible not only to controlthe use of encrypted contents information by the license informationcorresponding to the encrypted contents information but also to providea system for discriminating the officially copied contents informationfrom privately copied contents information by the presence of thedigital signature, for changing the reproduction form of the contentsinformation based on the discrimination results, and for reproducing inmore advantageous mode for the officially copied contents informationthan the privately copied contents information by pasting signature withthe secret key of the public key cryptosystem which only the contentsselling server authorized to sell the contents information knows to thelicense information corresponding to the encrypted contents information,which is the officially copied contents information. Consequently, it ispossible to prevent expansion of personal use and to protect thecopyright and the contents provider while permitting the privatelycopied contents information. In addition, when the contents informationis unjustly transferred to another recording medium, that is, copied,since the license information is dependent on the recording medium, forexample, the license information is unable to be decrypted, and as aresult, the contents information is unable to be decrypted.Consequently, whether it is the privately copied contents information orthe officially copied contents information, for the copy, the licenseinformation must be re-generated, and it is only the just recordingdevice which knows, for example, the function “f” that can re-generatethe license information, and the restriction to the number of copies isable to be definitely exercised, and thereby the unjust use can beprevented.

Other embodiments of the information recording and reproducing deviceaccording to the present invention will be described. The same portionsas those of the first embodiment will be indicated in the same referencenumerals and their detailed description will be omitted.

Second Embodiment

The reproduction device according to the first embodiment previouslydescribed premises to have plural kinds of contents information, andrequires a recording device for generating the plural kinds of contentsinformation, and as the second embodiment, the contents recording deviceis described. The present embodiment may be integrated with thereproduction device of the first embodiment to form a contentsrecording/reproduction device.

The overall configuration of the contents recording device related tothe present embodiment is shown in FIG. 21, and the processing flow isshown in the flowchart of FIG. 24. Referring now to the flowchart ofFIG. 24, the contents recording device of FIG. 21 is described.

To the contents input section 202, the encrypted contents information(Kc[C]) or non-encrypted contents information C is input together withthe encrypted digital license information L as the contents information(step S201).

The overall control section 201 determines the kind of the contentsinformation referring to the license header of the encrypted digitallicense information (steps S202, S204, S206). If the contentsinformation is the officially copied contents information (Yes of stepS202), the overall control section 201 sends these data to the privatelycopied contents generating section 204 and advances to the privatelycopied contents creation processing (step S203).

If the contents information is the privately copied contents information(Yes of step S204), the overall control section 201 sends these data tothe privately copied contents generating section 204 and advances to theprivately copied contents creation processing (step 205).

If the contents information is the original contents information (Yes ofstep S206), the overall control section 201 sends these data to theoriginal contents generating section 205, and begins original contentsgenerating processing (step S207).

By changing the recording technique in accordance with the kind ofcontents information as described above and providing the environment inwhich at most the privately copied contents information only isgenerated in the recording device, the officially copied contentsinformation put on the formal market and the privately copied contentsinformation is differentiated, and the value of the officially copiedcontents information is increased relatively, thereby contributing tothe expansion of the market of the officially copied contentsinformation.

Next, the privately copied contents generating section 204 of thecontents recording device of FIG. 21 is described in detail. FIG. 22shows a configuration example of the privately copied contentsgenerating section 204 and FIGS. 25 and 26 show a flow of theprocessing.

Referring now to the flowcharts shown in FIGS. 25 and 26, the privatelycopied contents generating section 204 is described.

When the privately copied contents information is recorded (copied),first of all, the encrypted contents information Kc[C], the encrypteddigital license information L, and copy form information Q are inputfrom the contents input section 204 b, and processing begins (stepS211).

The copy form information Q has a structure shown in FIG. 30. That is,in the copy form information Q, the category of contents informationafter the copy (category of copied contents information) and utilizationcondition of the copied contents information (utilization conditioninformation) are stated.

Now, the utilization condition information has a structure shown in FIG.31, comprises a digital output flag Fe, effective date information,effective number of use information, and number of copy restrictinginformation, which are information to be embedded in the informationstated in the digital license information and analog licenseinformation, respectively.

As will be clear in the following processing, these pieces ofinformation is not always reflected as they are in accordance with thecategory of the contents information after copy. As described later,each upper limit value of the utilization condition is specified inaccordance with the category of contents information after copy asdiscussed later, and it is not allowed to set the utilization conditionexceeding the upper limit value. By doing this, privately copiedcontents information, officially copied contents information, andoriginal contents information is discriminated for the use, and a systemsuited for profits of the contents provide is materialized.

Now, the inputted encrypted contents information Kc[C] and the encrypteddigital licensing information L, and copy form information Q are sent tothe control section 204 a, and the encrypted contents information Kc[L]and the encrypted digital license information L are sent to the contentsdecrypting section 204 e.

At the contents decoding section 204 e, same as contents reproduction ofthe contents reproduction device according to the first embodiment, theencrypted contents information is decrypted. That is, the media ID (MID)is acquired from the media M on the source side through the media IDacquiring section 206 (step S212), and using the media ID and hiddenfunction “f”, a license key w is generated at step S213 from arelational formula ofw=f(MID)

and the encrypted digital license information L is decrypted (stepS214). From the decrypted digital license information, the contentsdecryption key Kc is extracted (step S215). In addition, from thedigital license information, a certificator is extracted, and byverifying the certificator, the contents decryption key Kc is checkedfor freedom of error (step S216). And using the contents decryption keyKc, the encrypted contents information is decrypted, and the contentsinformation C is obtained (step S218).

The contents information C decrypted by the contents decrypting section204 e is sent to the analog license detection/modifying section 204 fvia the control section 204 a. Here, first of all, the contentsinformation C is sent to the data decompressing section 204 g, wherecompression of the contents information C is depressed (step S219), andthe depressed digital contents information C is D/A converted (stepS220), and the analog contents information Ca is obtained. From thisanalog contents information Ca, the analog license information isextracted (step S221), and the kind of the contents information isspecified by the copy information of the analog license information.

If the contents information of the source is the officially copiedcontents information (step S222), the copy information of the analoglicense information as shown in FIG. 5 is modified as the privatelycopied contents information (step S226), and, similarly, the number ofcopy restriction information of the analog license information is set tothe upper limit value permitted to the privately copied contentsinformation (step S227).

On the other hand, if the contents information of the source is theprivately copied contents information (step S223), the number of copyrestriction information of the analog license information is subtractedby one (step S224).

If the contents information of the source is neither the officiallycopied contents information nor the privately copied contentsinformation, the error is outputted (step S228).

The analog license information presently recorded is erased and theanalog license information generated in the foregoing processing isembedded in the analog contents information instead (step 225). Further,after it is A/D converted to the digital contents information Cd (stepS229), the contents information is sent to the data compressing section204 h and undergoes the compression processing (step S230), and newcontents information C is obtained.

The new contents information C is sent to the contents encryptingsection 204 d together with the contents encryption key Kc from theanalog license information detecting/modifying section 204 f via thecontrol section 204 a.

At the contents encrypting section 204 d, the inputted contentsinformation C is encrypted by the inputted contents decrypting key, andthe decrypted contents information Kc[C] is obtained (step S231).

On the other hand, the control 204 a refers to the digital output flag,effective date information, and number of effective use restrictionstated in the utilization condition information of the copy forminformation Q, and make sure these conditions do not deviate from therange of the privately copied contents information. If it deviates, thecontents utilization condition U is generated in such a manner that itcan be contained in the digital license information in the rangeauthorized in the privately copied contents information (step S232).

Next, the certificator MAC is calculated from the contents decryptionkey Kc and the contents utilization condition U (step S233). Thecomputation method is the same as the computation carried out forconfirming the certificator by the contents reproduction device of thefirst embodiment previously discussed.

Furthermore, to the part of the copy information of the license header,the information of the privately copied contents and others arecalculated and stored, and the digital license information of thecontents are completed.

Then, for encryption of the digital license information, from the targetside (recording side) media M′, the media ID (MID) is acquired throughthe media ID acquiring section 206 (step S235). From the acquired mediaID (MID), the license key w is generated at step S236 byw=f(MID)

This creation system is the same as the creation system of the licensekey generated for the encrypted digital license information L discussedfor the processing of the contents decrypting section 204 e previouslydiscussed. However, since MID differs from the case of the former, adifferent license key is generated.

By changing the data of the encrypted digital license information beforeand after the copy in this way, illegal copy is able to be prevented(even when the data is simply copied to other medium, it is unable to bedecrypted).

Using the license key w obtained in step S236, the digital licenseinformation Lo is encrypted and the encrypted digital licenseinformation L is obtained (step S237).

With the foregoing, all the data to be recorded are completed, and theencrypted contents information Kc[C] and encrypted digital licenseinformation L are recorded in the target-side media M′ via the contentsrecording section 208 and the license recording section 207,respectively (steps S238-S239).

Next, the original contents generating section 205 in the contentsrecording device of FIG. 21 is described in detail. FIG. 23 shows theconfiguration of the original contents generating section 205 and FIGS.27 to 29 shows the flow of the processing.

Referring now to the flowcharts shown in FIGS. 27 to 29, the originalcontents generating section 205 of FIG. 23 is described.

When the original contents information is copied, first of all, thecontents information C and copy form information Q are input from thecontents input section 205 b and processing begins (step S241).

The contents information C is sent to the analog license informationdetecting/modifying section 205 d via the control section 205 a, andfrom here, by processing of the data decompressing section 205 g, thecontents information is depressed (step S242).

The depressed digital contents information Cd is subject to D/Aconversion, and the analog license information is detected (stepsS243-S234). Here, if it is the original contents information, it is notdetected, but if part of the data is tampered and the contentsinformation is input by pretending to be the original contentsinformation, the error is outputted upon detection of the analog licenseinformation and the processing is ended (steps S245-S246).

If the source is the original contents information, whether it is copiedas the original contents information or as the privately copied contentsinformation is determined by the category of copy information of thecopy form information Q (step S247).

Because for the original contents information, the contents with thecopyright to users themselves as defined previously, the contentsinformation is able to be copied into the non-encrypted originalcontents information or privately copied contents information.Naturally, copying the contents as the original contents enablesreproduction under more advantageous conditions but if the author him orherself wants to set some kind of restriction to the utilization form inthe copied contents information, the object is fulfilled by recording itas privately copied contents information.

If the contents information should be copied as the privately copiedcontents information, it is necessary to advance to step S248 and recordthe analog license information in the contents information.Consequently, the analog license information is generated, the copyinformation is designated as the privately copied contents information,the number of copy restriction is set not to exceed the upper limitvalue of the number of copies permitted in the number of copyrestriction information contained in the utilization form information Q,the analog license information is embedded to contents information C,A/D converted, and then, further compressed by the data compressingsection 205 h, and a new contents information C is obtained (steps S248to S252).

On the other hand, when the contents information is copied as theoriginal contents information, it is necessary to advance from step S247to step S251, A/D convert without generating the analog licenseinformation (steps S248 to S250), carry out compression processing, andobtain the contents information C (steps S251 to S252).

The contents information C generated by the above-mentioned processingis sent from the analog license information detecting/modifying section205 d to the control section 205 a, and the processing procedure ischanged whether the contents information is copied to the privatelycopied contents information or to the original contents informationreferring to the copy form information Q by the control section 205 a(step S253).

First of all, when the contents information is copied to the originalcontents information, encryption is not required, and the licensegenerating section 205 c generates the digital license information andlicense header only are generated, and the copy information in thelicense header is designated as “original contents information” (stepS264), and the digital license information is recorded in thetarget-side media via the license recording section 207 (step S262).Now, the digital license information in the case of the originalcontents information is free of any encrypted part because only thelicense header exists, and the license key does not need to begenerated. Because the contents information C does not need to beencrypted, either, it is recorded on the target side media through thecontents recording section 208 as it is (step S263).

Next discussion is made on processing when the contents information isrecorded as the privately copied contents information. When the contentsinformation is recorded as the privately copied contents information(step S253), the contents information C is encrypted, and the encrypteddigital license information L containing the contents decryption key Kccorresponding to the contents information is generated, and recorded inthe media. The procedure is described sequentially.

The control section 205 a sends the contents information C to thecontents encrypting section 205 e, where an instruction is given to thecontents decryption key generating section 205 f and a contents key Kcis generated (step S254). With the generated contents decryption key Kc,the contents information C is encrypted (step S255), and the encryptedcontents information Kc[C] is obtained. The encrypted contentsinformation Kc[C] is delivered to the contents recording section 208 andrecorded in the target-side media (step S263).

On the other hand, after the contents decryption key Kc is oncedelivered to the control section 205 a, it is delivered to the licensegenerating section 205 c. At the license generating section 205 c, mediaID (MID) of the target-side media is obtained from the media IDacquiring section 206 (step S256), and byw=f(MID)

a license key w is generated (step S257).

The contents utilization condition U contained in the digital licenseinformation is determined in the range permitted for the privatelycopied contents information referring to the utilization conditioninformation of the copy form information Q (step S258).

Then, from the contents key Kc and the utilization condition U, acertificator MAC is generated (step S259). With this, the digitallicense information Lo is generated (step S260), and using the licensekey w generated previously, the digital license information isencrypted, and the encrypted digital license information L is obtained(step S261).

The obtained encrypted digital license information L is recorded in thetarget-side media by the license recording section 207 (step S262).

As described above, according to the contents recording device of thesecond embodiment, when the contents information (may be encrypted ormay not be encrypted) and the license information (may be encrypted ormay not be encrypted) added to the contents information, which isrequired for reproducing said contents information is recording in arecording medium, the category of the contents information input isdetermined, the license information is rewritten based on the determinedcategory and the information dependent on the identifier of therecording medium, the contents information is recorded in the recordingmedium together with the license information. The license informationmay be rewritten based on the utilization condition of the contentsinformation. In rewriting the license information, it is not allowed tobe rewritten into the license information of the officially copiedcontents information. Consequently, only the copy information which canbe only reproduced under the severer restrictions than the sourcecontents information is allowed to be generated, and the officiallycopied contents information put on the formal market and the privatelycopied contents information is differentiated, and the value of theofficially copied contents information is increased relatively, therebycontributing to the expansion of the market of the officially copiedcontents information. In addition, because in the license information,the information dependent on the recording medium is included, whetherit is the privately copied contents information or the officially copiedcontents information, for the copy, the license information must bere-generated, and it is only the just recording device which knows, forexample, the function “f” that can re-generate the license information,and the restriction to the number of copies is able to be definitelyexercised, and thereby the unjust use can be prevented.

Next description will be made on several modified examples (third tosixth embodiment) of the second embodiment.

Third Embodiment

When contents information other than the original contents information(particularly officially copied contents information) is generated(copied), it is desirable to degrade the contents to a proper level bythe privately copied contents generating section 204. This is becausethe degradation discourages the expectation to copying and promotes thesales of the officially copied contents information put on the formalmarket. In this sense, noise may be added to the contents information inthe analog license information detecting/modifying section 204 f or thecompression ratio in the data compression may be increased to achievethis scheme. For this purpose, two degrading methods are able to beassumed: a method for adjusting the compression ratio of the datacompressing section 204 h to cause degradation and a method forincreasing the degree of embedding when the analog license informationis embedded to cause degradation in the contents information.Particularly in the latter case, there is an advantage that the analoglicense information is difficult to be peeled.

Fourth Embodiment

It is able to design a recording device (or a recording/reproductiondevice) that does not admit the original contents information as a kindof contents information. The device of such kind is obtained byeliminating the original contents generating section 205 in theconfiguration of, for example, FIG. 21 and in the above description, byeliminating the processing concerning the entry of the original contentsinformation and the copy of the original contents information.

Conversely, when the entry of the original contents information ispermitted, a method for limiting the input terminals that recognizes theinput as the original contents information is assumed. According to thismethod, taking, for example, a mechanism for allowing the voice inputfrom the microphone terminal to be recorded as the original contentsinformation but the voice input from the radio terminal to be recordedas the privately copied contents information can determine the kind ofcopy information by the input medium, and even when the copy informationis not input in the format of the recording device, the voice not onlyis able to be recorded but also is able to determines whether the copyis from the original contents information or not.

Fifth Embodiment

The contents reproduction device of the first embodiment and thecontents recording device of the second embodiment have independentmechanisms, respectively, but it is also possible to consider arecording/reproduction device of an integrated form. In such event, itis possible to share the media ID acquiring section, data compressingsection, data decompressing section, etc., which are component elementswith the same functions.

Sixth Embodiment

There allowed to exist is a form in which the source contentsinformation to be input is limited to the analog contents informationonly, and copy to the privately copied contents information only isallowed. By doing so, when the digital contents information is recorded,the contents quality degradation is able to result from allowing thecontents information to pass the analog layer once, and degradationequivalent to that of conventional privately copied contents informationis achieved, and the privately copied contents information from theviewpoint of the contents quality is achieved.

The configuration of such contents recording device is shown in FIG. 32and the flow of the processing in FIGS. 33 to 34.

Referring now to the flowchart shown in FIGS. 33 to 34, the contentsrecording device of FIG. 32 is described.

The analog contents information Ca is input from the contents inputtingsection 301 (step S301). The input analog contents information Ca issent to the analog license information detecting/modifying section 302,where the analog license information is extracted (step S302) and therestriction of number of copies contained in the analog licenseinformation is confirmed to be “1” or more (step S303). If it is not “1”or more, further copy is unable to be generated, and the error isoutputted (step S304).

The cases in which the analog license does not exist or the restrictionof number of copies is “1” or more are discussed. If the analog licenseinformation does not exist, the restriction of number of copies is setto the upper limit of the privately copied contents information, and ifthe analog license information exists, the restriction of number ofcopies is subtracted by one and in either case, the analog licenseinformation with the copy information set to the privately copiedcontents information is generated, and if the analog license informationhas already existed, after it is removed, the analog license informationnewly generated is embedded in the contents information (stepsS305-306).

The contents information Ca with the analog license information embeddedis sent to the A/D converting section 303 via the overall controlsection 304, where using the contents decrypting key Kc generated by thecontents key generating section 309, the contents information C isencrypted and the encrypted contents information Kc[C] is generated(steps S309-S310).

The contents encrypting section 307 sends the contents decryption key Kcto the overall control section 304, while it is also sent to the licensegenerating section 306 together with the utilization condition Udetermined by the whole control section 304.

At the license generating section 306, the certificator MAC is generatedfrom the contents decryption key Kc and the utilization condition U, andthe digital license information Lo is generated. The generated digitallicense information Lo is sent to the license encrypting section 308,where using the license key w generated by the license key generatingsection 310, the digital license information Lo is encrypted (stepsS11-S314).

Now, the flow of processing by the license key generating section 310 isdescribed. At the license key generating section 310, the media ID (MID)for recording the encrypted contents information is acquired via themedia ID acquiring section 312 (step S312) and by the equationw=f(MID),

the license key w is generated (step S313).

Now, the encrypted digital license L is recorded to the medium via thelicense recording section 311 (step S315). Similarly, the encryptedcontents information Kc[C] is also recorded (step S316).

By integrating the reproduction device that does not admit the originalcontents information with the recording device of the present embodimentor using them in a pair, a contents recording/reproduction device withhigher security is able to be realized. That is, when the contentsinformation other than the recording/reproduction device of the presentinvention is input and recorded, the analog input only is admitted, andthe digital contents information record is restricted to the privatelycopied contents information. This means that even in the digitallyrecording and reproducing world, since the contents information oncepasses through the analog contents information, improvement in thequality is unable to be expected from the quality of the conventionalrecording/reproduction system, and this not only serves as a deterrentof copying but also relatively increases the value of officially copiedcontents information and the sales market of the officially copiedcontents information is able to be secured more definitely.

Seventh Embodiment

In the present embodiment, the contents selling device and the contentspurchasing device used for purchasing and reproducing the digitalcontents information from other party are described. Here one embodimentof a mechanism for purchasing and selling the digital contentsinformation, for example, via the Internet server or an automaticvending machine is described.

First of all, the embodiment of the contents selling device isexplained. The contents selling device means a selling device forgenerating and selling the officially copied contents information inresponse to the purchase request. In the present embodiment, for acontents selling server device, the shopping mall on the Internetmaterialized on the network is assumed.

FIG. 35 is an overall configuration diagram of the selling server, andFIG. 36 is the configuration diagram of the license generating section403 of FIG. 35.

First of all, referring to FIGS. 37 and 38 showing the flow of the wholeprocessing of the selling server, the selling server is described. Theselling server begins operation by receiving the contents purchaserequest from the client (step S401). As shown in FIG. 39, the purchaserequest information comprises the ID information of the client who madea purchase request, contents ID (CID) of the contents informationdesired to purchase, purchase utilization condition (Uc), media ID (MID)of the recording media for the client to record the contentsinformation, and the client address.

When the purchase request information is received, the selling serversends this to the overall control section 402, and sends the contents IDcontained in the purchase request information to the contents searchingsection 405, searches the contents database (DB) 407, and extracts thecontents decryption key Kc and the selling amount P (and depending onthe circumstances, encrypted contents information Kc[C]) (step S402).

Now, for the condition to take out the encrypted contents informationKc[C], for example, the contents ID is expressed with a sufficientlylarge bit number, and if there exists any redundant bit, one bit of theredundant bits may be used as a flag for determining whether theencrypted contents information should be transmitted or not.

Next (or simultaneously with the processing in contents searchingsection 405), the overall control section 402 searches the credit numberof the client from the client database (DB) 408 using the client ID as akey, and the credit is referred with the searched credit number (stepsS403 and S404). If the credit reference result evidences that thepayment is able to be made, the encrypted digital license information isgenerated based on the procedure described in detail as follows, and theencrypted digital license information is outputted to the client address(steps S405 though 407). If as a result of the credit reference, it isevidenced that the payment is unable to be made, the effect is notifiedto the client address. The notice and the output may be made byelectronic mail or when the network is directly connected, the networkconnected may be used.

Referring now to the flowchart shown in FIG. 38, the processing forgenerating the encrypted digital license information by the licensegenerating section 403 of FIG. 36 is described.

The license generating section 403 receives the entry of the media ID(MID) extracted from the contents decryption key Kc and the purchaserequest information outputted by the contents DB 407 and beginsprocessing (step S411).

First of all, the license generating section 403 determines theutilization condition U, generates the certificator MAC from thecontents decryption key Kc and the utilization condition U, andgenerates the digital license information Lo (steps S412 and S413).

Then, by the media ID (MID) input, the license generating sectiongenerates a license key w at step S414 byw=f(MID)

The license key generating section 403 c sends the license key w and thedigital license information Lo to the control section 403 b, and by thecontrol section 403 b, the license information Lo is encrypted togenerate the encrypted digital license information (steps S415 andS416).

Further, from the server secret key database (DB) 409, the key serversecret key Ks and the secret key ID (KID) are extracted (step S417), thedigital signature is affixed to the encrypted digital licenseinformation L with the secret key Ks (step S418), and adding thisinformation, the encrypted license L is generated. The generated digitallicense information L is outputted to complete the processing (stepS419).

This concludes the description of the contents selling device, that is,the selling server. Next description is made on the mechanism of thecontents purchasing device corresponding to the selling. The contentspurchasing device may be the reproduction device itself, but it is notalways the reproduction device itself, but may be any device such aspersonal computers, etc. or special-purpose device, to which network isconnected.

FIG. 40 shows the configuration of the contents purchasing device, andreferring now to the flowchart shown in FIGS. 41 to 42, the contentspurchasing device is described.

To the contents purchasing device, the contents ID of the contentsinformation to be purchased is input through the contents selectioninterface (IF) 501, and sent to the overall control section 502 (stepS501). The contents selection IF 501 may be of the type to input thecontents ID from the keyboard, or the user may input the contents ID bysearching and specifying the contents information with the name ofsinger or composer used as a key by the special-purpose search softwareor input software.

The overall control section 502 receives the contents ID entry andextracts the media ID (MID) from the media which records the contentsinformation via the media ID extracting section 504 (or which hasalready recorded the contents information) (step S502).

Then (or simultaneously), from the client information storing section505, the client ID (of the purchaser), the client address are extracted(step S503), and based on these pieces of information extracted, thepurchase request information as shown in FIG. 39 is transmitted to theselling server (steps S504-S505).

In the present embodiment, the client information is stored in theclient information storing section 505, but this section may be changedto the entry from the outside to carry out the same processing.

In addition, if the contents ID is transmitted from the contents sellingdevice to the encrypted license L (if there is no encrypted contentsinformation on the contents purchasing device side, together with theencrypted contents information Kc[C]) based on the purchase requestinformation, the contents selling device records these in the media fromwhich the media ID is extracted (steps S511-S512).

This concludes the description on the configuration of the contentspurchasing device and the flow of processing. From the above-mentionedconfiguration, it is clear that the contents purchasing device is ableto be integrated with the contents reproduction device. That is, theconfiguration of the reproduction device shown in FIG. 8 is functionallyindependent fro the configuration of the selling client shown in FIG.40, and a device which incorporates both functions is able to beconfigured. Similarly, the same relation holds for with the contentsrecording/reproduction device described in the second embodiment.

Consequently, it is able to assume a system for integrating the contentsselling device with the contents purchasing device. This is a devicelike an automatic vending machine of the contents information, and isable to be realized by using the fee collecting section 404 in theconfiguration of the contents selling device of FIG. 35 for thecoin/bill detection/storing device in the automatic vending machine andrecording the generated encrypted license L (and encrypted contentsinformation) to the media via the media recording section 503 in theconfiguration of the contents information purchasing device of FIG. 40.

By achieving this kind of automatic vending machine, the client is ableto bring the media to the automatic vending machine and purchase thecontents information and the license. Needless to say, it is possible toconfigure an automatic vending machine with the contents purchasingdevice only. In such event, the device must be connected to the contentsselling device via telephone line, etc.

As described above, according to the present invention, the contentsinformation copied by the properly authorized party (officially copiedcontents information) is able to be distributed in the more advantageousform than the contents information copied without proper authorization(privately copied contents information). As a result, the demand ofofficially copied contents information is increased, and the informationdistribution mechanism suited for interests of the contents provider,contents user, and electronic equipment provider can be provided.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the present invention in its broaderaspects is not limited to the specific details, representative devices,and illustrated examples shown and described herein. Accordingly,various modifications may be made without departing from the spirit orscope of the general inventive concept as defined by the appended claimsand their equivalents.

1. A method of generating license information related to digitalcontents of information comprising: receiving a purchase request from auser, the request including an identification of digital contentsinformation, a utilization condition of the digital contentsinformation, and a media identification of a media to which the userrecords the digital contents information, the digital contentsinformation comprising officially copied contents information which iscopied under a right for selling the contents information and privatelycopied contents information which is copied without a right for sellingthe contents information, and the utilization condition information ofthe privately copied contents information being more restricted than theutilization condition information of the officially copied contentsinformation; determining a content key for the digital contentsinformation based on the identification; generating a certificator basedon the content key and the utilization condition; generating a licensekey based on the media identification; encrypting the content key, theutilization condition, and the certificator based on the license key;generating a digital signature of encrypted content key, encryptedutilization condition, and encrypted certificator based on a secret key;and generating a digital license information including a header, theencrypted content key, the encrypted utilization condition, theencrypted certificator, and the digital signature.
 2. The methodaccording to claim 1, further comprising: encrypting utilizationcondition information of the encrypted digital contents information, theutilization condition information including effective date informationand effective number of times information by the information dependenton the recording medium.
 3. The method according to claim 1, wherein thegenerating a digital signature comprises generating the digitalsignature using a secret key information of a public key encryptionsystem.
 4. The method according to claim 1, wherein the licenseinformation includes utilization condition information includingeffective date information and effective number of times information,the utilization condition information of the privately copied contentsinformation being more restricted than the utilization conditioninformation of the officially copied contents information.
 5. The methodaccording to claim 1, wherein the license information includesinformation indicating whether or not the contents information isoriginal contents information which is compressed but is not encrypted.6. A license information generation device configured to generatelicense information of digital contents information comprising: areceiving unit configured to receive a purchase request from a user, therequest including an identification of digital contents information, autilization condition of the digital contents information, and a mediaidentification of a media to which the user records the digital contentsinformation, the digital contents information comprising officiallycopied contents information which is copied under a right for sellingthe contents information and privately copied contents information whichis copied without a right for selling the contents information, and theutilization condition information of the privately copied contentsinformation being more restricted than the utilization conditioninformation of the officially copied contents information; a determiningunit configured to determine a content key for the digital contentsinformation based on the identification; a certificator generating unitconfigured to generate a certificator based on the content key and theutilization condition; a license key generating unit configured togenerate a license key based on the media identification; an encryptingunit configured to encrypt the content key, the utilization condition,and the certificator based on the license key; a signature generatingunit configured to generate a digital signature of encrypted contentkey, encrypted utilization condition, and encrypted certificator basedon a secret key; and an information generating unit configured togenerate a digital license information including a header, the encryptedcontent key, the encrypted utilization condition, the encryptedcertificator, and the digital signature.
 7. The license informationgeneration device according to claim 6, further comprising: anencryption device configured to encrypt utilization conditioninformation of the encrypted digital contents information, theutilization condition information including effective date informationand effective number of times information by the information dependenton the recording medium.
 8. The license information generation deviceaccording to claim 6, wherein the signature generating unit isconfigured to generate the digital signature using a secret keyinformation of a public key encryption system.
 9. The licenseinformation generation device according to claim 6, wherein the licenseinformation includes utilization condition information includingeffective date information and effective number of times information,the utilization condition information of the privately copied contentsinformation being more restricted than the utilization conditioninformation of the officially copied contents information.
 10. Thelicense information generation device according to claim 6, wherein thelicense information includes information indicating whether or not thecontents information is original contents information which iscompressed but is not encrypted.